Automatic air-feed regulator for rock drills



F. M. sLATER AUTOMATIC AIR FEED REGULATOR FOR ROCK DRILL Filed Nov. 2, 1921 P o/ E 5 f J 1.47/2 .,0\\\v14 5- /w/ o @MAMMA Jung 30, 1925' g Y a, Y a f I Patented June 30, 1925.

UNITED ASTATES PATENT OFFICE.

FRED Tlf. SLATER, OF EASTON, `PENNSYLVANIA, ASSGNOR TO INGERSOLL-RANID COMPANY, 0F JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

AUTOMATIC AIR-FEED REGULATOR FOR ROCK DRILLS.

replication mea november e, 1921.y seran no. 512,188.

To all whomzt may conc-era:

Beit known that I, FRED M. Sii-tran, a citizen of the United States, and a resident of Easton, county of Northampton, and State of Pennsylvania, have invented a certain Automatic Air-Feed Regulator' for Rock Drills, of which the following is a specification, accompanied by drawings.

Thisinventio-n relates to fluid actuated rock drills of the hammer type, which may or may not have automatic rotation, but relates more particularly to automatic regulation of the pressure in the feeding element of such rock drills.

This feeding element may be an air feed piston and cylinder, or other fluid actuated device and the objects of the invention are to enable the pressure in the feeding element to be automatically regulated by means controlled by the pressure in the said element itself, preferably without varying the supply to the feeding element.

To these ends the invention consists of the device shown in one of its preferred forms in the accompanying drawings, in which Figure l is a longitudinal sectional elevation of a rock drill embodying the invention,

Figure 2 is an enlarged detail longitudinal sectional view of the regulating valve shown in one position, and

Figure 3' is a similar view showing the valve in another position.

Referring to the drawings, a stope drill is illustrated in the figures having the cylinder A and front head B provided with the rotation sleeve C through which the drill steel D extends in position to receive the iinpact blows of the hammer E, An independent tluid actuated rotation motor is provided in this instance for rotating the drill steel, a` gear motor being indicated, having the gears F, only one of which is shown in Figure l, in the motor casing formed by the back end portion G of the cylinder. A head block G is located between the cylinder portion G and the head K of the fluid pressure cylinder H, which is provided with the piston J and piston rod K, having the rock engaging foot L. The cylinder A, back end portion or motor casing G, head blocl: Gr and feed cylinder H are suitably. held together as vby means of the usual through bolts (not shown). One of the gears F of the motor, is operatively connected through a suitable shaft O and pinion P, meshing with the gear Q, on the rotation sleeve C, for rotating the drill steel.

A rod H having the head J" held between the. bushing L and the head K, of the feed cylinder, is slidably but nonrotatably co11- ne-cted to the piston J in any suitable manner, as by means of the rib H2 operating in a corresponding groove in the said pis.- ton. By this means the feed cylinder and parts carried thereby cannot rotate relative to the piston J and piston rod K.

Fluid pressure, as live air, is supplied to the machine at the inlet R and is controlled by a suitable throttle valve S, having the usual handle T. Fluid passes to the feed cylinder H through the passages U and V as indicated by the arrows. A rotation handle W is suitably mounted on the head block Gr.

In order-to provide means controlled by the pressure in the feeding element for automatically regulating the feed pressure, prefer a valve construction, one form of which is illustrated in the drawings. A sleeve X is mounted at the upper end of the feed cylinder H formed with a suitable valve chest Y at one side communicating with the interior of the feed cylinder through the passage Z. A valve plug or cage a is suitably secured within the valve chest Y as by means of the screw threads Z), and within the valve cage a, a slidable cylindrical valve o controls the exhaust from the feed cylinder.

As shown, the inner portion Z of the valve cage or plug, is of reduced diameter, so that the head e of the valve is subjected to the pressure in the feed cylinder.` A suitable spring within the Valve, bearing against the end g of the valve plug, opposes the vHuid pressure on the valve head e and tends to maintain the valve closed, as shown in Figure 2. The valve is provided with a series of ports it in its walls and the valve cage is provided with a port j so that when the pressure within the feed cylinder H exceeds the pressure of the spring j', the valve c will be moved longitudinally as indicated in Figure 3, and bring one or more of the ports t into position to permit fluid pressure to pass from the feed cylinder H through the passage Z, port and one or more of the ports it to the outlet ports ,7c in the end g of the valve plug. As the pressure in the feeding element is reduced, the spring will again close that-)the feed pressure Wllfbe'regulated without varying the supply of fluid pressure to the feeding elem-ent.

A11 automatic air feed regulator valve for rock drills adapted `to .be controlled 'by the pressure Huid in the feeding element, oomprsng a valve ohes't'opeu'at one Aend and mounted at one sidev of the cylinder of the feeding element, a passage ait Jhe s'delofthe Valve 'chest 'affording lcommurieat'oh Ibetween thev valve chest and eedzeylihdeu a valve Cage' In the form off a hollow cylindrical plug, having an nnergportionfol .reduced diameter removably. secured Within the pressure in the cylinder.

the vopenV epd of `the valve lehest, :an `atmospheric iporttn the ouhernd foi fthe Valve eage, a holloweeylindrcal valve closed at its -in-ner -endfformng :a Lheadaa-nlrsldwble with :ink the- -valye gage, and @a valve tha-ving a series of ports in its Walls adapted to cooperate with -the-passageaatjthe side of the valve chest, and a spring Within the Valve opposing 'the pressure '-lud-exerted on the valve head, whereby one or moreof the valve ports are brought mto jcommf-uruoatlon Wl-th the feed cylinder passage n accordance-with In testimony whereofv I have sighedy this specification. A t

' FRIED "MS-LATER. 

